If the values don’t actually exist in any table, you can SELECT them as literals from any table or view, such as dual or one of the data dictionary views. (The view all_views is handy because everyone can SELECT from it, and it has hundreds of rows.) The pseudo column ROWNUM is n for the nth row selected, and you can map this to your values using CASE (as shown below) or DECODE.

INSERT INTO table_x (id, dt, name)
SELECT CASE ROWNUM
WHEN 1 THEN 201
WHEN 2 THEN 202
WHEN 3 THEN 203
WHEN 4 THEN 204
WHEN 5 THEN 205
END
, TO_DATE ( CASE ROWNUM
WHEN 1 THEN '01-Jan-2008'
WHEN 2 THEN '01-Feb-2008'
WHEN 3 THEN '01-Mar-2008'
WHEN 4 THEN '01-Apr-2008'
WHEN 5 THEN '01-May-2008'
END
, 'DD-Mon-YYYY'
)
, CASE ROWNUM
WHEN 1 THEN 'Aardvark'
WHEN 2 THEN 'Bass'
WHEN 3 THEN 'Cedusa'
WHEN 4 THEN 'Dodo'
WHEN 5 THEN 'E. Coli'
END
FROM all_views
WHERE ROWNUM